Why is Christophe LeMaitre so Damn Fast?

Christophe LeMaitre is one fast sumbitch. As a matter of fact, he’s the fastest Caucasian in the history of track & field. At only 21 years of age, he’s the only Caucasian to officially run 100 meters in less than 10 seconds (he actually did so at age 20). To date, 80 sprinters have broken the 10-second barrier, but only one of them is Caucasian. Christophe has run the 100m in 9.92 seconds and the 200m in 19.8 seconds, and he’s faster than Asafa Powell and Tyson Gay (and possibly Usain Bolt) were when they were 20 years old.

Over the years, many theories have been proposed as to what limits acceleration, maximal speed, and 100m sprint performance. Is absolute force what’s truly important, or does the direction of force application matter? Do increased vertical force and the generation of high levels of stiffness get you on and off the ground more quickly? Is horizontal force more important to help push you further down the track? Is the resultant ground reaction force vector (combination of vertical and horizontal forces) critical, or is it more complicated? Is the “force” portion of the power formula (P = FV) more important than the “velocity” portion, or vice versa? Do faster sprinters have lower contact times? What about stride lengths and stride rates? Do faster sprinters have higher body masses, thereby allowing them to produce greater force? Do they have longer limbs than their slower counterparts? What are the most important “sprint” muscles?

These are just some of the questions that sports scientists and track & field coaches are trying to figure out, and French researcher JB Morin is leading the way with some amazing research over the past several years.

Mechanical Determinants of 100m Sprint Running Performance

Recently, Morin and colleagues decided to analyze LeMaitre and other sprinters in an attempt to figure out what makes LeMaitre faster than his competitors. Here’s a LINK to the abstract. This study is one of the coolest studies I’ve ever read and I commend the researchers for putting together such a comprehensive study in order to advance our understanding of sprint biomechanics. Here’s what they did:

Subjects:

The researchers examined 13 subjects. Nine of them were P.E. students who had been exercising regularly (including sprinting) over the past six months but were not sprint specialists. Three of them were National level sprinters in France. And one was Christophe LeMaitre; the fastest dude in all of Europe (in the world top 4 in 100 and 200m at the 2011 World Championships in Daegu). Though many studies in the literature have examined high-level sprinters, very few have experimentally studied a world-class sprinter, which makes this study highly valuable.

Methods:

Two main measurements were taken for each subject:In addition, anthropometric data was collected

A 100m sprint on a standard field track, and

A 6-second sprint on a specialized torque treadmill (to date the only of this kind) that measured 3-dimensional forces, velocity, power, and other important variables of interest

The researchers collected a ton of data, both on the track and at their lab, and conducted an impressive number of analyses

Results:

This particular paper has contributed very heavily to the body of knowledge. In fact, it took me a few reads to adequately understand all of the findings due to the physics and mathematics involved in the paper. Since there were so many findings, I’ll just list them in bullet-point fashion:

Mean and peak propulsive power in the horizontal direction, as measured on the instrumented torque treadmill, were significantly correlated with maximum speed, 100m sprint time, and the distance covered over a 4-second interval. The latter were the most relevant and simple to understand acceleration and sprint performance variables considered by the group of scientists.

The researchers were able to create a force-velocity line by plotting the dots created by the horizontal force and corresponding velocity values averaged for each running contact phase, from the step at which max horizontal force during the sprint was produced (typically one of the first three steps), to that when maximum velocity was reached. By doing so, they were able to draw and study subjects’ “force-velocity” profile (i.e. the overall incline of their individual force-velocity linear relationship), i.e. on what balance between these capabilities (force or velocity) does subjects’ power output depend.

By extending the line to the vertical and horizontal axes, they were able to obtain theoretical maximums of horizontal force production (the hypothetical maximum amount of force production possible absent of time requirements) and velocity production (the hypothetical maximum velocity possible absent of external forces). These maxima are important as they characterize the mechanical limits of neuromuscular output in sprint running, and can not be reached in experimental conditions.

The theoretical maximum horizontal force that sprinters could produce was not correlated with any of the performance variables, whereas the theoretical maximum horizontal velocity that sprinters could achieve was significantly correlated with all performance variables. In other words, a velocity-oriented power profile seems critical to speed and 100m sprint performance, not a force-oriented power profile.

The researchers calculated what they call an “index of force application/orientation technique” by plotting the dividend of the horizontal force and total force (they call this RF which stands for “ratio of force”) from the second step of the sprint until maximum speed was reached and then creating a line-of-best fit, allowing them to calculate the slope. This gives an indication of the sprinter’s ability to continue to create a forward-oriented total ground reaction force (GRF) at increasing speeds. This index is highly correlated with all measures of sprint performance; maximal speed, 100m sprint time, and 4-s distance. In fact, Christophe Lemaitre (the fastest runner in the group) had the highest index whereas the slowest runner had the lowest index.

Low contact times, high step frequencies, and low swing times were significantly correlated with 100m sprint performance, which surprisingly was not the case with high step lengths and aerial times.

As you can see, the index of force application technique is the highest correlate of maximal speed, followed by maximum horizontal power output. Average 100m speed is most related to measures of horizontal power and force. Distance covered over a 4s interval is most related to horizontal power output as well.

Horizontal GRFs are much more related to sprint performance than vertical or resultant GRFs.

Theoretical maximum horizontal velocity is more related to sprint performance than theoretical maximum horizontal force. In fact, when comparing these two extremes between Lemaitre (fastest sprinter in the group) and the slowest sprinter in the group (he recorded a 15.03s 100m sprint), Lemaitre possessed a theoretical max horizontal velocity and theoretical max horizontal force of 14.0 m/s and 8.47 N/kg, respectively, whereas the slowest sprinter possessed a theoretical max horizontal velocity and theoretical max horizontal force of 8.28 m/s and 6.82 N/kg, respectively. So Lemaitre’s theoretical max horizontal velocity is far superior (69% higher) to the slowest sprinter, whereas his theoretical horizontal force is only 24% higher than the slowest sprinter.

Correspondence With Morin

I was able to correspond with JB Morin and attain some very interesting information that cannot be found in the published study (including the detailed chart below).

First, though the National sprinters along with Lemaitre did possess better vertical stiffness than the non-sprinters, leg stiffness did not vary between Lemaitre and the National sprinters and surprisingly the non-sprinters as well.

Second, some of Lemaitre’s results compared to his peers are quite startling. He achieved:

2 standard deviations (5.5% faster) ahead of the National sprinters for the 100m sprint time

2 standard deviations ahead of the National sprinters for maximum velocity power output

10% greater metabolic power than his National peers (even higher at the beginning of the 100m sprint)

Third, some of Lemaitre’s results were on par with his National peers. He achieved:

Similar levels of theoretical maximal horizontal force

Similar levels of aerial time, swing time, and step length

Similar levels of vertical and total force production per unit of bodyweight (vertical force only 3.24% higher and total force only 3.68% higher)

Similar levels of BMI (actually slightly lower) and L/H ratio

Forth, at every single sprint velocity, Lemaitre is able to produce more horizontal force than the National sprinters, who are able to produce more horizontal force at every sprint velocity than the non-sprinters, despite the fact that each group’s theoretical maximal horizontal forces were similar (8.54 N/kg for Lemaitre, 9.28 N/kg for Nationals, 8.40 N/kg for non-sprinters).

17.3% higher horizontal rate of force development (3.02 standard deviations) than his National peers (obtained by dividing net horizontal force by contact time), but only 6.45% greater vertical rate of force development (1.2 standard deviations) than his National peers. However, the horizontal and vertical RFDs were much higher in the National sprinters than the non-sprinters.

Based on these data, it can be deduced that what’s important is not the maximum amount of horizontal force capabilities, but the relative (per bodyweight) horizontal force at any given velocity (and especially at higher velocities).

*Metabolic power was estimated following the methods proposed by di Prampero in 2005. Click HERE for a link to that paper.

Limitations

The only main limitation of the study is that it was conducted on a torque treadmill. This type of treadmill does have a different “feel” to it compared to sprinting on a track, as it involves more forward lean. However, treadmill sprint times and 100-m performances were significantly correlated to track field times (the fastest runners on the track appear to be the fastest runners on the treadmill, and the slowest on the track appear to be the slowest on the treadmill). Moreover, the treadmill allows for the collection of highly meaningful data including the GRFs over the entire sprint run (records GRFs for every single step). This data collection allows for the calculation of RFs and the index of force application, which seems to be the most highly correlated factor relating to maximal speed. This is currently the only way to get such data, until fully instrumented 100-m tracks are made available…

What Future Research Needs to Determine

Like all excellent studies, this paper should lead to further research for various questions, including:

What training methods best produce horizontal force and power during sprint running?

What muscle groups are the most concerned? JB Morin and his group are currently testing the hypothesis that the hip extensors (glutes and hamstrings) play an important role in this forward orientation of the resultant force.

Does each sprinter have an optimal force/velocity profile, as recently shown for vertical jump performance by researcher Pierre Samozino (Click HERE for a link to that abstract)?

What are the best cues for sprinting to allow them to increase horizontal force and power?

If Lemaitre continues to get faster over time, what variable changes will help him achieve his speed increases (for example, increased resultant force capability, increased BMI)?

Conclusion

What makes Christophe Lemaitre so damn fast? It isn’t vertical force, total force, resultant force, stiffness, step length, or theoretical maximum horizontal force. His effectiveness of force application onto the ground (quantified through Morin et al.’s index of force application: the slope of the line of best fit formed with the plots of the ratio of horizontal to total force for each step of the sprint) is much higher than his peers. He produces much higher relative net horizontal force and power throughout the sprint. The velocity component of his force-velocity profile is much higher than his peers. And his step rate is higher and contact time is lower than his peers. This shows that throughout the race and especially at high speeds, he continues to produce high levels of net horizontal force.

Domenic; all we could do is speculate about his technique…whatever he’s doing in that regard seems to be working for him, but maybe he can improve upon it over time (this is not my area of expertise). As for power, he is producing more horizontal force at every possible velocity compared to his not-as-fast counterparts. That’s what makes him so special.

Literally dozens of research articles on this subject. This info is not drastically new. Treadmill creates more forward lean than normal, therefore more horizontal force than normal over-ground contact. Was 6 second sprint from initial standstill, or was it a “6 sec fly-in?” All thisng must be considered. Most sprinters (elite, national class, collegiate, etc.) have almost indentical “air time.” Stride frequency is increased by reduced ground contact time. Elite sprinters move legs through a greater range of motion during swing phase, and (according to almost all studies) apply force for only 25-30% of stance phase. High hip flexor activity after mid-stance characteizes elite sprinting technique. Morin has done some good work previously. Most research data (Bolt, Powell, Gay, etc)indicate high vertical forces, accentuated front side mechanics, minimal back side mechanics, and high hip flexor and hamstring activity. Wiemann and Tidow indicate that since EMG activity of the glute did not change with velocity/effort change in sprint measurements,it was primarily a stabilizer instead of a primary propulsor.

Dozens of articles on sprinting? Dozens involving force plates? Dozens involving torque treadmills over a 6-sec interval with high level sprinters? Please be more specific.

Dozens involving sprinting and forces? If that’s your contention then I disagree.

Not drastically new? It’s brand new. Morin’s Index of Force Application is genius. This study also shows the importance of the velocity side of the FV profile.

I mentioned the lean but it doesn’t discredit the entire study. 6-sec sprints were from a standstill.

Research data on Bolt, Gay, Powell? I haven’t seen this. Do you have a link or reference?

I see pictures of Usain sprinting and it looks like he’s extending his hips pretty far to me.

Sure force application might only be during first part of stance phase but so what? It’s still in a range that is pretty “extended,” and strengthening this region should be helpful (especially since this region isn’t strengthened sufficiently from squats).

And there’s conflicting research regarding glute activity…since you’re so well-versed in the research I thought you’d know this. Do you really believe that the glutes are just a stabilizer during sprinting?

According to a number of EMG’s, glutes act to decerlate the swing leg and assist in driving the leg to contact. Peak values for the glutes are attained just prior to contact and during the braking phase of stance. Once the body moves just past mid stance the glutes cease activity. Yes the glutes provide propulsion during the downward phase of swing and assist in facilitating the continuation of backward swing of the leg during the first part of stance. Hamstring activity continues longer during stance as part of Lombard’paradox and because the hamsting is actually trying to close the knee angle. Faster runners extend less at takeoff at the hip and the knee. What you are witnessing is sometimes referred to as “follow through” after the impulse through mid stance. You should read the USATF manual by Ralph Mann. Eventhough it appears as such, elite sprinters are not trying to “push” themselves down the track. It looks like that, but scientific data states otherwise. Actually, there are dozens of research articles regarding joint moments, muscle sychronization, force vectors, etc. Most of them (EMG’s included) say the similar things. I haven’t seen much conflicting data on glute activity during sprinting, and I’ve been coaching sprints and hurdles over 40 years, and have worked with some of the best coaches, athletes, and researchers in the world. Force APP Index is a new way of formulating information, but similar info has been reported before.

Not trying to say the glute is not important, but most research indicates that the hams or hip flexors are more of a limiting factor than the glutes in fast running. According to all EMG studies, glutes to not fire the leg through to takeoff,even in block starts.

Not trying to discredit the value of glutes in running. They certainly play a significant role in sprinting. The issue lies with the fact that most trainers don’t know exactly how the glutes function during sprinting and how their firing pattern is synchronized sequentially during the gait cycle. Contrary to popular belief, the majority of glute activity occurs during front side mechanics prior to mid stance.

I agree with you that they cannot be sufficiently strengthened by squatting. I have read your columns and blogs for some time and use some of your exercises in my training. Your exercises definitely result in more activation than squatting. They are both innovative and effective. Also help reduce external rotation during posterior chain training.

Interesting article by Ralph. He has analyzed several of my athletes at previous High Performance Summits. His book on the Mechanics of Sprinting and Hurdling is the most in depth book, other than Franz Bosch’s, available. And John is both a friend and competitor.

Regarding looking right and flying right, Mann states in his book on page 139, “the muscular demands around the hip are complex, demanding, and counter- intuitive……….the greatest hip forces are produced during the Front Side of the sprint action…..The final challenge is one of concept and has proven to be the most difficult. Whereas, it is commonly believed, and intuitively supported, that a sprinter should use their hip extensors to drive the body down the track during ground contact, the data tell us otherwise. In fact, the best of the elite sprinters only emphasize leg extension for the first 25 percent of ground contact. The last 75 percent of ground contact, the elite sprinter is actually using high levels of hip flexor activity to stop the backward rotation of the upper leg.” On page 141 in the Chapter Summary, “The key to producing elite sprint performance is emphasizing Front Side mechanics while minimizing Back Side mechanics. It is critical to achieve Front Side mechanics coming out of the start. If this is not achieved, then it cannot be regained later in the race.”

The glute has an active role in sprinting, but it’s different than intuition would indicate.

Thanks for the exercises and training tips. They are challenging and work very well.

JF, first off I commend you for being an evidence-based coach. I can tell you’re very informed and I appreciate your comments. I might email you some newer studies (sucks – I had around 400 studies on sprinting, glutes, and hammies all organized in New Zealand but when I moved back to AZ last month I had to ditch all of the articles as it was going to cost $1,000 to ship it to the states) that show glute max contraction peaking at footstrike. I’ve said this many times, but I believe that the hammies are the most important speed muscles. And I’d love to read more of Mann’s articles (many of them are very hard to pull up as my University and other Universities don’t have access to the journals he published in back in the day). I have several of them but not all, and I’ve read his book (Mechanics of Sprinting and Hurdling) but I disagree with the conclusions on forces at max speed (not the data…but the conclusions) and will write a blog about it in the near future. No disrespect meant to Mann, he could teach me a ton about sprinting, but I have a different take on the data (and I’m reasonably good at math and physics) that I’m eager to present. I also disagree with Mann’s conclusions about hip forces; greatest hip torque occurs at footstrike and I’m not sure what angle of hip flexion this equates to (a study by Cavagna showed around 30 degrees) but I’m sure it’s in between 30 degrees and neutral. Would you agree? And this range, I believe, is the most critical range of hip extension as it’s responsible for the absorption of braking and vertical forces and the production of propulsive and vertical forces.

Where the hip extensors stop activating is not so relevant as we know it’s somewhere around neutral (probably 20 degrees of hip flexion) so we need to be strong and stable in this range. Sure there is stored energy involved, sure at top speed the contractions are more akin to isometric contractions, but the glutes are heavily involved in absorbing braking forces, and we still don’t know if Bolt and Lemaitre are using their glutes more so than other sprinters. What I do know is that anecdotally the hip thrust seems to help some sprinters get faster and it’s good to include in programming since it helps build full-spectrum hip extension strength to make up for the squat’s lack of end-range torque (but the squat has great flexed-range torque). Clearly we can see from Morin’s new study that the velocity aspect of the power formula is more important than the force side of the formula, but there are various reasons why heavy strength training can improve neuromuscular power (as you know).

I need to read Bosch’s book as I’ve been meaning to for ages…just been so busy.

So I suppose that in addition to Mann, I also disagree with Weyand, Mike Young, and John Goodwin, but I have tremendous respect for those guys and I acknowledge that they could teach me a ton about sprinters and training sprinters. At the end of the day I care more about science than appearing right, so if I’m wrong I’ll fully admit it. And until researchers get to the bottom of the controversy we all need to be respectful of each other’s theories.

Thanks again for your post! I appreciate you being respectful and I commend you for your quest for knowledge.

Very interesting stuff. I think the better the glutes and hams work in unison when making contact and then extendingfor that very brief amount of time is what produces the faster sprinter. If you were to fire the glues much more than the ham you would be what I like to call “yanking” the ground toward you, equallying a “yanked hamstring”..not fun. Bret, please send me more studies, findings, you have on this subject. I have been a student of sprinting for 23 years. Thank you.

Ralph’s comment to me in an email: “We know WHAT a an elite sprinter needs to do, but we don’t know how to teach them to do it.” That is, there’s currently no reliable method for getting someone to develop a new set of movement patterns that result in faster sprinting.

Can you say more about how they’re defining horizontal force velocity? (otherwise it sounds like they’re saying “if you run faster, you’re faster”)

Peter Wayand at Baylor has, for years, been discussing Mass Specific Force (the amount of force produced in relation to bodyweight at the correct angle). It sounds like this research is validating that.

I’d be so interested in seeing how horizontal/vertical forces change over the acceleration curve. Among my peers (I’m an almost-50 year old Masters All-American sprinter), the thought is: faster drive phase — with more horizontal force — equals higher top end speed, and; applying mostly vertical force in the correct direction at the top end equals holding that speed longer.

Steven, one of Morin’s papers shows a typical horizontal and vertical force curve over I believe the course of a 6-second sprint. Of course, this is on his torque treadmill…we currently can’t do this overground.

As for your first question, I believe the treadmill measures horizontal forces via a Kistler force plate positioned underneath (the sprinter is tethered to the wall 2m behind). I believe velocity refers to the speed of the belt.

As for Ralph Mann and Peter Weyand, these guys are brilliant and have advanced the knowledge of sprint biomechanics. And now Morin is building upon their knowledge and helping to separate out the forces in sprinting.

As for your last statement, I disagree but this would require a separate blogpost.

Very cool and interesting review Bret! This is the study you were telling me about on the phone. I’m really looking forward to seeing what LeMaitre can do at the Olympics this summer! I’m also interested in how we can use this information to enhance the training process for maximal speed development.

The human body is dynamic, elastic, and organic, not rigid and mechanical. We should look at it as a collection of synergic components not prime movers, stabilizers, agonists, and antagonists. Look at is this way: Hip flexion ends glutes, hams, and adductors fire extending the hip. Foot contact, the opposite hip wants to drop, the preloaded glutes stop this, reaction force is stored and released in the IT band. Hams are flexing the knee and maintaining knee angle against the knee extending force produced by the hip extending glutes and adductors (THIS IS THE HORIZONTAL FORCE). Quads are extending the knee against gravity, but they aren’t working hard because they are assisted by hip extension (glutes and adductors). This is your vertical force. Hip hyperextension is produced by arm swing transferred to the hips by the lats and flexing spinal erectors. Also the forward swinging hip of the opposite leg helps swings the supporting side of the pelvis back. The back swinging supporting side of the pelvis helps swing the flexing side forward. Now toe lift and the heal approaches the glutes. This preloads the sartorius, rectus femoris, and tensor fascia lata. The extended spine preloads the psoas and abbs this results in a powerful forward swing which again assists the opposite leg’s extension and reloads the hams, glutes, and adductor mag of the swinging leg. High knee lift is needed so the hip flexing leg can clear the ground and the supporting leg is doing the least amount of vertical work possible to keep the hams loaded to the max. Unnecessary knee extension unloads the hams and energy is wasted as vertical motion. This can go on forever especially if we consider rotational axial torque and the adductor contribution to hip extension, flexion, and pelvic stability. I hope this makes sense and you get my point. I’m not saying anyone’s wrong or right. Just a new way of observation and thinking is needed. I apologize in advance for any grammatical errors its early.

E Nist – I agree with you, but to me that’s all biomechanics. We can measure the actions of the muscles, their lengths, activations, strains, joint torques, various measures of stiffness, forces, powers, etc. And your explanation was beautiful! Thanks for the post.

Thanks for the comprehensive writeup. I won’t pretend to understand all the math but I did have a question about replication–is the treadmill essentially bespoke or easily recreated? I feel that equivalent experimental subjects would be easy to find stateside. One quibble–Lemaitre is not from the Caucasus region so “Caucasian” is not really descriptive. I think you’re safe in just saying, “white,” because that conveys the significance of his awesome performances just as well:http://blogs.discovermagazine.com/gnxp/2011/01/stop-using-the-word-caucasian-to-mean-white/

Hi Nandalal, Morin’s treadmill is one of a kind; I think he has a brilliant team of engineers at his college who helped with it’s manufacturing (could be wrong though). And I think Morin himself has a background in engineering as well, could be wrong about that too. But there are Woodways that are similar, but they have a load cell from behind that measures the horizontal forces. Sorry about the Caucasian confusion!

Does the treadmill actually ‘encourage’ more forward lean?. ie an increase in lean angle = increased gravitational torque = increased horizontal forces. If so, doesn’t the study seem some what biased towards what would be a predictable conclusion?.

Andy, I guess “encourage” is a mild word; it requires forward lean. But I think the treadmill torque is countered by the tether, so it doesn’t influence forces to much degree. At any rate, Morin and colleagues will be conducting some overground studies in the near future where they will critique their own work by making comparisons with their treadmill work to the overground work in terms of force and power production, etc.

This is a great question. You get forward lean during acceleration, so I suppose the lean would impact max speed results more so than acceleration results. I suppose we’ll have to wait until overground tests are conducted to see if results are duplicated.

Hi Andy, thanks for the feedback,
yes as Bret mentioned field force-plate data will soon come and bring support / discussion to our treadmill study. I can’t wait for these data to be published…
As to the correlations, remember that the correlations were tested between what subjects were ABLE to produce on the treadmill and their FIELD 100m performance. So basically should the treadmill impose different sprint mechanics (which I obviously don’t contest) than on the field, it allowed us to measure what athletes could produce during a maximal sprint effort. Then, these mechanical features of their effort were correlated (or not) to their real 100-m field performances. So for instance when we show a correlation between SF and 100-m sprint performance, it should be read as “the guys able to produce the highest step rate on the treadmill were those who ran the fastest 100-m, and vice versa”.
I acknowledge all the limitations the treadmill brings (far less than existing treadmills such as woodways, though), but I also recognize and appreciate the very qualitative data it gives. Overall, I think a positive and constructive debate must focus on what new data our study brings, rather than the data it does not.
Last, from a more philosophical point of view (this comment is not a specific response to you Andy but a more general statement), you have two possibilities in our field of science, either you wait for the totally perfect measure (100-m force plates + 3D mocap for all lanes during the Olympics final) and this is easy work because it will likely not happen soon so some will have all the time to criticize everything else (systematically “worst” than this ideal situation). OR, you try to do things with the devices your epoch allows you to use, and you put data forward. This is hard work, but it allows discussion, controversy, and this is sound because it makes thing go forth.
Karl Popper told us that what can be refuted has a scientific feature. It is a pleasure for me to bring data and refute / confirm them, or see them refuted by others. I mean, refuted by DATA of others….this point is crucial, bring data to refute other data otherwise the discussion is not fair.
Thanks Andy and others for your posts, and thanks again Bret for the opportunity to share views

Bret, he is not the only Caucasian to run that way. In 1988 I ran 9.6 100’s 10 times in Ft. Worth texas starting the clock first using acutrack. Ran by myself for 4 coaches. 4.19 40 out of the blocks on FAT. Job and a family, divorce kept me from the world of Track and Field. Ran qualifying times for US trials in 1988 and ’92. Long, Long story my friend but true. I’m 48 now and can still fly. Now I teach others to run fast. Don’t expect you to believe it just needed to say it out loud. BTW, I can give Bolt .20 of a sec if I had him. Haven’t seen the white kid run yet but I will!!!

I was wondering what your take is on good ankle dorsi flexion for the sprint. What if you have 2 identical athletes with same sprint characteristics but 1 does have good dorsiflexion and the other points his toes towards the track just before landing. How much would that affect his 100 meter time?